sanderson



N0. 6I8,236. Patented Ian. 24, I899. T. C. SANDEBSDN. DRIER FOR WH-ITELEAD, 81.12.

(Application filed Feb. 8, 1897.)

2 Sheets$haet I.

(No Model.)

. Wyn/My? 1: News nrrsns c o. worn-mac WASHINGTD No. 618,236. Pa tentedJan. 24, I899.

T. C. SANDERSON.

DRIER FOR WHITE LEAD,I&C-

' (Application filed Feb. 8, 1897.)

(No Model.) 2 Sheets-Sheet 2.

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ilNilE o STATES ATENT DRIER FOR WHITE LEAD, 86C.

SPECIFICATION forming part of Letters Patent No. 618,236, dated January24:, 1899.

Application filed February 8, 1897. Serial No. 622,406. (No model.)

To all 10700772 it may concern:

Be it known that I, THOMAS ORIsr SANDER- sON, a subject of the Queen ofGreat Britain and Ireland, and a resident at Upton Manor, London,England, have invented certain new and useful Improvements in Apparatusfor Drying lVhite Lead, Colors, and other Powdery, Granular, r NodularSubstances, of which the following is a specification.

This invention relates to the dryingof white lead, colors, and otherpowdery, granular, or nodular substances, (hereinafter referred to r aswhite lead and it consists of an improved arrangement of apparatusdesigned to effect such purpose and characterized by the combination ofa central chamber (hereinafter referred to as the drying-chamber)through which the white lead is slowly traversed and is meanwhilesubjected to the drying action of heated air (hereinafter referred to asthe drying-air traveling in areverse direction and side chambers(hereinafter referred to as reheating-chambers which communicate withthe drying-chamber at the lower and upper parts thereof and serve toreheat the drying-air as it becomes cooled by evaporating moisture fromthe white lead and descends to the lower part of the drying-chamber andpasses into the reheating-chambers, causing it to reenter thedrying-chamber at its upper part in a reheated state, and so onrepeatedly, whereby an effective drying action is obtained and theapparatus is caused to work much more economically.

On the accompanying drawings, Figure 1 represents a sectional elevationon A B, Fig. 2. Fig. 2 represents a sectional plan on O D, Fig. 1; andFig. 3 represents a sectional elevation on E F, Fig. 1.

o. is a main chamber within which the drying and reheating operationsare effected and which may be made of any desired length, according tothe nature of the substance intended to be treated therein. At the upperpart of one end the chamber is formed with an inlet ct for the hotdrying-air, and at the lower part of the other end it is formed with anoutlet a for the air laden with moisture evaporated from the white lead.For the greater part of its length the chamber is partitioned off intothe said drying-chamber a and reheating-chambers a by brattices 0. whichextend from near the fioor to near the roof of the chamber a, leavingbottom and top passages a a between the chambers a a, the latter ofwhich are closed at the ends, as at a Each of the chambers 00 isindependently heated to a temperature equal to or exceeding that of thedrying-air supplied to the chamber a by steam-heated gill-fitted pipesa", (or by any other suitable means,) arranged at the lower part of thechamber, steam being admitted to the piping by a connection a at anyconvenient part or parts of its length. The pipes a may be duplicated ormade with greater radiating-surface toward the ends of the chamber atwhich the moist white lead is introduced, so as to raise the temperatureof the drying-air as it travels along the chamber a and meets wettermaterial.

The white lead is carried through the chamber a on a slowly-travelingendless web (or webs) b, which at the supply end is mounted on an adjustable roller b, and at the discharge end is mounted on adriving-roller 17 to which a slow rotary motion may be communicated byany convenient means, and at its intermediate part is supported byrollers b The inlet for the White lead is fitted with steam-heated rolls0, by which the white lead is fed onto the web I) in a flaked state andin a sufficiently heated condition to prevent moisture from thevapor-laden drying-air it meets from depositing on it.

In the operation of the apparatus the hot drying-air supplied to thechamber a flows in a gentle current over the slowly and reverselytraversing layer of white lead carried by the web 6, and as it getscooled by evaporating moisture from the white lead descends over theedges of the web to the lower part of the chamber a and flows thencethrough the passages a into the chambers a wherein it is then reheatedby the steam-piping a and is caused to ascend within such chambers andto reenter through the passages a the chamber a wherein it againdescends onto the White lead, and as it is again cooled by evaporatingfurther moisture therefrom again descends into the chambers a and isagain reheated, and so while traveling from end to end of the chamber ait is caused to circulate in a circuitous course through the chambers aa alternately, being repeatedly reheated suificiently to maintain itsdrying capacity throughout its course until it passes beyond the inletof the moist white lead, when it descends to its outlet 0 whence it isled to a chimney. I

The repeated reheating of the drying-air, so as to maintain its dryingcapacity throughout its course, is of particular advantage in the dryingof white lead and other substances the dust of which is injurious orobnoxious, as it enables the drying treatment to be car ried out in along continuous chamber, through which the white lead may be slowlytraversed without being disturbed either by the traversing apparatus orby the drying air and without any of its dust being raised within thechamber, in consequence whereof the chamber itself is kept free fromdust and may be entered by workmen with impunity, and the effiuentmoisture-laden air is discharged at the outlet at free from dust, andconsequently the dangerous nature of the operation is considerablylessened. With the same object provision is also made for enabling thedried white lead to be discharged without any of its dust being drawnback into the chamber, and to this end the chamber is fitted with adischarging-hopper d, which is separated therefrom by a plate (1, havingopenings d d for the outward and return passage of the web I), protectedby aprons cl, the opening d through which the web carrying the driedwhite lead issues from the drying-chamber into the hopper, being furtherprotected by being fitted with a roller 61 for supporting the web andwith a loosely-mounted roller (1 which rests lightly upon the issuingdried white lead and accommodates any irregularities in the thicknessthereof, rolling the same down and preventing any dust being raised asthe white lead issues from out of the drying-chamber. The hopper is alsoconnected by a passage d with a stithechamber, (not shown,) throughwhich by means of an attached fan or the like a sumcient current of airmay be caused to flow from the hopper to counteract any tendency of thecurrent of drying-air through the drying-chamber to draw any dust fromthe hopper thereinto. The returning part of the Web is freed from anyadhering particles of the white lead by a revolving brush d driven fromthe roller 11 It is not essential that the white lead should betraversed through the drying-chamber on a traveling web, as a series oftrays or other suitable carrying means may be used for the purpose.

When the improved drying apparatus is adapted to the drying of tea leafand other bottom throughout the length of the chambers, areceiving-hopper at one end of the drying-chamber, the endless carrierpassing through the drying-chamber and into said hopper through openingsin a wall separating V the drying-chamber and hopper, and apronsprotecting the openings through which theendless carrier passes into thehopper and back into the drying-chamber, substantially as and for thepurposes described.

2. In a drying apparatus the longitudinally-extending drying-chamberprovided at each side with reheating-chambers in commucation with thedrying-chamber at top and bottom throughout the length of the chambers,a receiving-hopper at one end of the drying-chamber, the endless carrierpassing from the drying-chamber into the hopper through openings in awall separating the dryin g-chamber and hopper, rolls located beneaththe endless carrier at the openings where it passes into the hopper andback into the drying-chamber, and a roll above the carrier where itpasses from the drying-chamber into the hopper, substantially as and forthe purposes described.

3. In a drying apparatus, the combination of thelongitudinally-extending drying-chamber, reheating-chambers on bothsides thereof and communicating therewith at both the top and bottom ofthe chamber throughout the length of the drying and reheating chambers,a hotair inlet at one end of the dryingchamber and an air-exit at theopposite end, a receiving-hopper at one end of the dryingchamber, anendless traveling carrier passing through the drying-chamber and intosaid hopper, an inlet for the material at a point in the drying-chamberabove the endless carrier, and heated rolls at said inlet between itandthe endless carrier, substantially as and for the purposes described.

Signed at London, England, this 13th day of January, 1897.

THOMAS CRISP SANDERSON. lVitnesses:

CHARLES AUBREY DAY, ALFRED CHARLES DAY.

